digit_to_number  2963 src/lread.c      for (int digit; (digit = digit_to_number (c, radix)) >= -1; )
digit_to_number  4503 src/lread.c      int leading_digit = digit_to_number (*cp, base);
digit_to_number  4508 src/lread.c          for (int digit; 0 <= (digit = digit_to_number (*++cp, base)); )